Some semiconductor light emitting devices including light emitting diodes (hereinafter “LEDs”) and laser diodes (hereinafter “LDs”) have pad electrodes and an electrically-insulating protection film on a multilayer semiconductor light emitting portion, which is composed of a plurality of semiconductor layers. Current is supplied to the semiconductor layers through the pad electrodes. The electrically-insulating protection film electrically insulates the pad electrodes from parts of semiconductor light emitting devices peripheral to the pad electrodes, and protects the semiconductor layers.
In particular, in the case where the pad electrodes are formed on the same side, when the pad electrode formation surface serves as a main light outgoing surface (face-up mount manner), the pad electrodes absorb light emitted light from the light emitting portion. For this reason, the pad electrodes may reduce the light outgoing efficiency. From this viewpoint, a variety of shapes, materials, arrangements and the like of the pad electrodes have been researched and developed.
A semiconductor light emitting device is known which includes a carrier electrode electrically connected to a transparent electrode layer for supplying carriers to semiconductor layers through the transparent electrode layer, and a wire-bonding pad electrode electrically connected to the carrier electrode, the pad electrode being arranged at a position outside the surface of the transparent electrode layer, for example, at a position on the surface of substrate or the like (e.g., Patent Document 1). In this semiconductor light emitting device, since the transparent electrode layer on the upper surface of the semiconductor layer almost entirely opened, light can outgo from the entire surface of the semiconductor light emitting device.
Also, a face-up chip type semiconductor light emitting device is known which includes a transparent positive electrode composed of a transparent electrode formed on a semiconductor layer and a bonding pad electrode formed on this transparent electrode, the bonding pad electrode including a reflective layer at least on a part of the surface of the bonding pad electrode in contact with the transparent electrode (e.g., Patent Document 2). In this semiconductor light emitting device, it is possible to suppress reduction of light emission caused by light absorption on the contact surface between the bonding pad electrode and the transparent electrode. As a result, it is possible to improve the light outgoing efficiency and thus to increase light emission intensity.